Synopsis

The remains of Cadogan West were discovered in a subterranean tunnel near Aldgate Station, his skull fractured. Sherlock Holmes found himself perplexed by the keen interest his brother Mycroft was taking in the affair. Mycroft revealed that the confidential blueprints for a novel submarine had been in the deceased's possession, though three of the ten pages were now missing. Acting as an agent of the British Government, he requested that Holmes recover the lost documents.